"I think clearly from what we've seen he's got intent, but the second piece is capability," former senior U.S. intelligence official Phil Mudd told ABC News. "He's been out of this business a long time so whether he's retained the capability is an open question. Whether he can resuscitate it, I think, is an even bigger question."

Gadhafi had been in the process of dismantling a stockpile of highly lethal mustard gas when a popular uprising put his 42-year reign in jeopardy. International monitors gave Gadhafi a deadline for this May to complete the dismantling but he has not yet completed it.

"It's clear that he has some mustard agent left," said Charles Duelfer, a former U.N. weapons inspector. "To use that, to drop it on somebody, you need to put it in something. And so far as anyone's been able to tell, he doesn't really have munitions to effectively use that. So I think that the military risk posed by this is relatively small."

On ABC's "This Week with Christiane Amanpour," chairman of the Joint Chiefs of Staff Michael Mullen said the remaining amount of the chemical was being "very closely monitored."

"I haven't seen it as a problem thus far," he said.

Concern over a possible terrorist attack directed by Gadhafi was raised Friday when White House terrorism advisor John Brennan told reporters the Libyan leader "has the penchant to do things of a very concerning nature."

"We have to anticipate and be prepared for things that he might try to do to flout the will of the international community. Terrorism is certainly a tool that a lot of individuals will opt for when they lose other options," he said.

Gadhafi's History of Terror Connection

Any attack on Americans would not be the first terror strikes linked to Gadhafi.

Last month, Libya's justice minister said he had "proof" Gadhafi directed the deadly attack on Pan Am flight 103, which killed 189 Americans when it blew up over Scotland in 1988.

Two years earlier, two Americans died in an attack on a German disco popular with American servicemen. In retaliation, then U.S. President Ronald Reagan ordered an airstrike on Gadhafi's personal compound.